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# Width Length Ratio

59 Threads found on edaboard.com: Width Length Ratio

## hysteresis of latch comparator?

try to make the width-length ratio of M9 and m10 different. two tips to form a hysteresis: the first is positive feedback. the second is that the circuits for two cases(vp>vn and vp

## A question on decrease output impendence of EA of LDO

for a buffer without negative feedback, the minimum output resistance is about the reciprocal of the transcondance, so if you need to get a smaller output resistance, all you need to do is to increase the transcondance(Eg:increase the current and the width-length ratio,sometimes using nmos rather pmos due to mobility). it's theoretically (...)

## Optimize for bandwidth in IE3D

I'm simulating a patch atenna. It simple to use the optimizer for finding the feeding point for a perfect match at the resonance frequency. But is there a way of also optimizing the antenna for maximum bandwidth? If the antenna height and dielectric is chosen, then the bandwidth is proportional to the width/length (...)

## transistor size for threshold voltage

In a typical inverter, NMOS pulls the output to low, while PMOS pulls the output to high. To increase the threshold, you need to increase the strength of the NMOS and/or reduce the strength of PMOS. The strengh of a MOSFET is decided by its W/L (width/length) ratio. The bigger this radio is, the stronger this MOSFET is. So now you know what to do.

## HFSS, How to ground Coplanar waveguide structure?

width and the height of the waveport definitely affect the impedance. If I remember right, the ground rules are 1. width of the waveport should be 5 times the g/s/g and 2. height should be 4 times the substrate's height. Of course, the integration line can be drawn either from the signal to ground line or the other way. I also found (...)

## How to determine MOS Switch aspect ratio?

Hi there, Currently, I am a student and working OTA with switch-capacitor CMFB and later going to switch-capacitor amplifier design. I am wondering which is the best MOS switch aspect ratio. Say, for TSMC 0.35um technology with 5v process, the minimum length is 0.5 micron. So how can I choose the W/L for NMOS switches in switch-capacitor CMFB

## Long Width, 4:1 current mirror layout

If you design low power circuits. I think you still layout like finger. The width is finger in W/L > 1 transistor, but in your transistor length is finger.

## How to calculate W/L ratio for rail to rail opamp?

hi! use lower currents, they result in low power and higher gain. try 10 mA biasing currents. use this reference. what software are you using? try plotting vgs-vt (for turn on of transistor) and vds-vdsat (for saturation) versus width. keep length at the minimum 0.35 um. you will find w

## what is the term for the width of MOS is smaller than Length

We often use this type MOS as large resistor. I wonder if there are some rules in thumb for using this "inverse W/L ratio" transistor.

## problem with sweeping the W/L ratio

There is no parameter in the model called "w/L ratio". You have to make W and L variables and number of fingers is not a relevant parameter for what you want to achieve. If you want L fixed and W to vary, make length a variable (call it x for example) then make width a varible called k*x, where k is the desired W/L ratio. (...)

## How to find gate width for irregular MOS shapes?

Hi, For simple rectangular MOS transistors, it's easy to identify width and length depending on direction of current flow. If you've complex irregular MOS transistor (not like a spider :D but mostly like a rectangle having many glitches from one or both sides), is there a scientific method in this case to define W and L? Sometimes current flo

## Width of wire in RF IC circuit layout?

Is there anything else I need to pay special attention to about the width and depth of the wires in a RF IC design layout (Cadence)? When you route your signal lines, don't forget the ground return. Both are equally important. Sounds trivial, but when I see layouts of RF circuits for EM modelling, many people seem to

## CMOS Transistor size ratio

... Can I simplify it to 3/2? So that I get strait lambdas? Sure; that's fine! To my second question, I have read from other sources that a rule of thumb is that the with of the PMOS should be twice the with of the NMOS because of the mobility in the material. The actual silicon m

## How to place the transistor of desired WL ratio in cadence manually in Layout Edi.

Hi all, My questions are as //.///I am newbie in cadence. 1)I want to draw the FETs manually In mircowind software by clicking on MOS icon we can fill it there the length and width to draw the MOS in the layout. Can we draw the layout similarly in Cadence Layout editor without the need to exec generate from all sources button.? 2) how

## How to get the 4WY WILKIN POWER DIVIDER S(3,2)parameter value more than -34DB

You need 100 ohm resistance in the TFR. If the sheet resistance is 100 Ohm/square, make TFR length = width.

## Where to define the V-I characteristics of a new created device\part(cadence)

Where to define the V-I characteristics of a new created device\part. e.g., I have to use MOS and I created my own part using ?NEW PART? in ?USER DEFINED PROPERTIES? i added new property width, length but where I have to give the characteristic equation which defines the relation of voltage, current, W/L ratio and other parameters.

## Very small notch (and feed width) for a inset-fed microstrip antenna, is it correct?

Hello! I'm designing a microstrip antenna which is going to be fabricated by drilling it out of a FR4 laminate with the specs: {e}_{r} = 4.3 h = 0.08cm For the frequency 866 MHz (using it for RFID), the parameters i've calculated are: W = 10.640 cm {e}_{eff} = 4.230 L = 8.346 cm inset length, y0 = 2.875 So f

## Is it possible to have Aspect ratio of less than 1 in analog circuit design i.e. W<L

I m using 120nm width and 800nm length for some it appropriate to use this much high value of length. Yes, totally ok! Some simulation models would warn you if you'd use a too large (or too small) aspect ratio, because the sim. model then wouldn't be accurate enough, but this usually applies

## "Length of MOSFET" is a design variable or not......

Hello the minimum length cannot be used in the analog design circuits, usually you need minimum of 2*min L and that because of : 1. minimum length has worst case matching 2. has higher channel length modulation that we never like since it will degrade the mos transistor output impedance and hence degrade the design of the current (...)

## Analog layout: Length & Width of MOSFET

Can anyone explain me clearly how does change in L & W of MOSFET cause variations in its characteristics. What all changes with L and W respectively and in which way?

## 555 monostable pulse width modulator

I think the 'tinny' reference was mine. To change the mark/space (on/off) ratio of the output you have to change the relative rates at which the capacitor on pin 6 charges and discharges. The schematic shown is clearly labelled "monostable" which means it has one stable state and applying a pulse to it's input (pin 2) makes it switch state until

## How to select appropriate ohm/square to achieve 100 Ohms?

I need S matrix of 100 Ohm thin film resistor. Would be great if s2p file covers bandwidth of 6-20GHz, but i'll be greatful for anything :> anyway i've tried to simulate response in sonnet. However i don't know how to select appropriate ohm/square to achieve 100Ohms :< So if you have simulated results in sonnet/hfss or other fullwave simulator and

## About TSMC 0.18um device model

depending on the length and width range of the transistor, the nmos or pmos section will be selected out of 12 cases.

## precise resistor how design?

If your using a resistive divider, only the ratio between resistors matters. Go to the process specification sheet and get the matching parameter of the resistive material you are planning to use (say Ao). Then you compute the standard deviation of each resistor, if proper layout techniques are used, as sigma=Ao/SQRT(W.L), where L is the total

## Branch Line Coupler Problem

Hi, theory doesn't take into account the effect of discontinuities (basically T junctions). If aspect ratio (line width/line length) is mild, i.e. length is considerably larger than width, you could try re-optimizing the coupler. Otherwise discotinuities are coupled (meaning that they are not seperated (...)

One thing bothers me for a long time. I know that circuit deisgn based on CMOS process, we choose biasing current or voltage, the length and width of the MOSFET for the target performance. But for BJT process, what kinds of parameters are chosen for consideration?

## Transistor and current ratios

If we have 2 MOS with exactly the same VDS and VGS, the same lengths, but widths in the ratio say 25:1. Why shouldn't the currents be in the ratio 25:1? I am asking this because simulations don't show the current ratio to be 25:1.

## novice for nourishment

The FET is basically a resistor (called channel) between the source and drain terminals, that is controlled by the gate terminal. So, if the gate voltage level creates carriers in the channel, then the resistance between source and drain is small. IF the gate voltage does not create the carriers in the channel, the resistance is very high. So,

## a question about bandgap circuit

The lateral Poly-PNP (PPNP or LPPNP) bjt is called poly because the base width is defined by the gate poly channel length. It is in effect an 5-terminal device. P: Gatepoly B: Base NWELL E: Inner P+ Region C: Outer P+ Ring The current gain is w/o an N* buried layer between 2-10. That is enough to use the PPNP as an amplifier. The collector

## Question in FloorPlanning

aspect ratio = width of chip/length of chip =1 means it is square chip core utilization = how many % ur design should accoupy in ur core area = basically choose 70% core utilization then only tools can put clock buffer when u do CTS etc remaining 30 % should used for inserting clock buffers and timing (...)

## Help me size input transistors for a differential amplifier

There are several equations you need to balance that most books (like Grey + Meyer) will give details on. Being an IC designer, I can tell you how I would get to the first-cut rough sizing. Firstly, the W/L ratio of the diode NMOS should be such that the net current density is approx. 1uA/square. So if your width is 2, and your length is (...)

## two stage ota design problem.

I was doing parameter analysis, setting the width of driver nmos of second stage as the parameter, doing dc sweep in cadence, there is really no much margin for the size. I mean sometimes, the size has to be exact to make sure the device in sat region. that's why I was worrying that it might cause problems consider the process variations. I was us

## HFSS Transformer simulation problem

Hi, tompson, Don't worry, " Initial mesh, process mesh3d : Unable to recover all the surface triangles." might be caused by the large ratio between the layers' length/width and thickness. If you have very thin layers, please merge it into other layers. In simulation, the simpler substrate definition, the better. Hope this helps, Rur

## ultra short channel mosfet

it means that channel lenght is short :D, u know the MOS is isolated gate device, where the gate potential "metal, infact polysilicon" is used to control the flow of the current in the MOS , the metal gate dimension are length "L" and width "W" , the current is proportional to the aspect ration W/L"this means that aboslute values are not (...)

## standard cell library achitecture

1. X1 is when minimum length/minimum width nmos transistors are used in the gates? 2. The difference between CLKBUF and BUF is that CLKBUF is designed with a lot more care payed to matching rise/fall delays through the cell. 3. You pick a maximum load used in your design and maximum allowed slew. Then evenly space out N (mostly 4-6) characterizat

## Help me saturate this inverter !

hi! using hspice? try parameter sweeping the length and width. then look at the .lis file. find the width and length combination that results in saturation. Ü - al

## Questions about increasing inverter threshold voltage and calculating delay

Please help me provide the answers of the following. How do you size NMOS and PMOS transistors to increase the threshold voltage? Explain sizing of the inverter . Draw Vds-Ids curve for a MOSFET. Now, show how this curve changes (a) with increasing Vgs (b) with increasing transistor width (c) considering Channel length Modulation. Gi

## Matching Pair for layout design

The bias will change when VDD, corner, temperature and resistor variation. I don,t know your application, So I cann't comment more about design.Maybe you don't care the bias variation, and the slew rate symmetry. "but different width is okay to apply in the layout design? " You can let the width of large MOS and small MOS's ratio is (...)

## gate or transistor sizing in detail

you gotta understand one thing... The W and L of all the transistors in a IC are not the same and this variation is done through transistor sizing and also once the IC is out of the foundry you cannot change anything in the IC i.e. the width of the channel can get modulated that is all... it cannot be changed....

## Modelling transmission lines as Capacitors

If it is a low enough frequency, it looks like a lumped capacitance. If it is a high enough frequency, it looks like a multimoded blob of stuff that needs an electromagnetic simulation program (sonnet, etc) to accurately model. If you cut down the width and made the length longer, then it might look enough like a piece of microstrip. That is why

Usually the parasitic of Current mirror is not critical. And is 50/0.5 is the total size? if it is 500/0.5 and the other is 20/0.5, the ratio will be too large, you'd better use the high swing cascode mirror. And 0.5u length is too small for current mirror. Beside, which circuit does the current mirror use? I think 50/0.5 is the

## hfss cpw size with very thick substrate

Hi, I am not actually new to HFSS, but I am struggling with a problem. By designing a cpw transmission line I have problem with the cpw size. g-s-g= 50 um h(substrate)= 400 um following all the tips in the various tutorial the width of my waveport shopuld be at least 200 um...which is fine.....for the height of the port I would have 4*h=1

## What's exactly meant by technology shrinking?

when the characteristic length is scaled down from 65nm to 45nm, it indicates the channel length decreases. accordingly some other parameters such as oxide thickness, metal width, impurity concentration, etc. also change.

## How to solve HFSS out of memory error?

Hello, guys: I got some problems in my hfss simulation. My case is a very thin film antenna, around 1um in thickness. I know the large ratio of length/width to thickness is bad for meshing and simulation, but I have to. Every run ends with errors as followed. Now I attach my project here. Could you please try to run it and comment? (...)

My guess is that you are running into problems with M3 & M4 going into linear region rather than saturation, starving the current out of the folded stage. You can check this by verifying the current levels in each leg of the amplifier. There are a couple of things you could do to prevent this: 1- Make M15 longer channel length with very narro

as I stated, in the read side, 4 data out of every 5 read clocks , like 0 1 2 3 x 0 1 2 3 x in the write side, every write clock per data, like 0 1 2 3 0 1 2 3 accoring to the freq ratio, the duration of 4 data write is equal to 5 data read. assuming write data width equal to read data width. assuming no latency when re

## How can I improve the gain of CMOS Gilbert cell mixer?

I have tried out the things you have suggested. Increasing the L of the transistors makes the gain worse as expected since gm is inversely proportional to sqrt(1/L) and the gain is theoretically (2/pi)*Rload/(Rs+ (1/gm)). So I want that gm as high as possible. I was sugesting increasing L for the load transistors. Accordi

## How to design log periodic antenna

I'm designing a printed LPDA, my question is how to choose the width of the antenna boom? is there any formula or relation between boom width and the widths of the dipoles?

## Multi finger transistor layout...

Finger width is not relative to lamda.

## Encounter Ant type error meaning

hi , Pleas refer the folowing blog for this. It will provide you indept knowledge about the Antenna Effects and how the rules comes from the foundry and how its codded in the different Tool. VLSI concepts: Antenna Effects Just in short Antenna ratio = 2/W2*l L: f